As a technology regarding the realization of high-speed transfer or the efficient use of a radio resource in radio communication, a cooperative transmission technology based on multiple input multiple output (MIMO) has been known.
The MIMO is a technology by which a plurality of radio devices cooperatively transmits data using radio waves of the same frequency with their respective transmission weights. The plurality of cooperative radio devices is called a cluster. Based on the radio propagation characteristics between a terminal device and the radio devices, the radio devices constituting the cluster transmit radio waves with the addition of transmission weights so that the receiving power to receive data at the terminal device becomes great. As a result, the terminal device is allowed to receive the data included in the radio waves of the same frequency. Since the plurality of radio devices transmits data with a single frequency, the MIMO is advantageous in that the effective use of a frequency resource is made possible.
A technology regarding a controller is described in Japanese Laid-open Patent Publication No. 2012-75104.    Non-patent document 1: 3GPP TS36. 211 V13. 1. 0 (2016-03)